Paraffin alkylation

ABSTRACT

A process for the alkylation of alkane with olefin or olefin precursor such as an oligomer of tertiary olefin comprising contacting a liquid system comprising acid catalyst, isoparaffin and olefin in concurrent downflow into contact in a reaction zone with a disperser mesh under conditions of temperature and pressure to react said isoparaffin and said olefin to produce an alkylate product is disclosed. Preferably, the liquid system is maintained at about its boiling point in the reaction zone. Unexpectedly, the olefin oligomers have been found to function as olefin precursors and not as olefins in the reaction. Thus, for example, a cold acid alkylation using an oligomer of isobutene (principally dimer and trimer) with isobutane produces isooctane with the isobutane reacting with the constituent isobutene units of the oligomers on a molar basis. The product isooctane is essentially the same as that produced in the conventional cold acid process.

[0001] This application claims the benefit of provisional applicationNo. 60/313,987 filed Aug. 21, 2001, provisional application No.60/323,227 filed 09/19/01 and provisional application No. 60/334,560filed Nov. 30, 2001.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to the alkylation of paraffinichydrocarbon feed stocks. The present invention provides both animprovement in the operating conditions and the feed stock for acidparaffin alkylations.

[0004] 2. Related Information

[0005] The common objective of most alkylation processes is to bringisoalkanes (or aromatics) and light olefins into intimate contact withan acid catalyst to produce an alkylation product. In the petroleumrefining industry, acid catalyzed alkylation of aliphatic hydrocarbonswith olefinic hydrocarbons is a well known process. Alkylation is thereaction of a paraffin, usually isoparaffins, with an olefin in thepresence of a strong acid which produces paraffins, e.g., of higheroctane number than the starting materials and which boil in range ofgasolines. In petroleum refining the reaction is generally the reactionof a C₃ to C₅ olefin with isobutane.

[0006] In refining alkylations, hydrofluoric or sulfuric acid catalystsare most widely used under low temperature conditions. Low temperatureor cold acid processes are favored because side reactions are minimized.In the traditional process the reaction is carried out in a reactorwhere the hydrocarbon reactants are dispersed into a continuous acidphase.

[0007] Although this process has not been environmentally friendly andis hazardous to operate, no other process has been as efficient and itcontinues to be the major method of alkylation for octane enhancementthroughout the world. In view of the fact that the cold acid processwill continue to be the process of choice, various proposals have beenmade to improve and enhance the reaction and, to some extent, moderatethe undesirable effects.

[0008] U.S. Pat. No. 5,220,095 disclosed the use of particulate polarcontact material and fluorinated sulfuric acid for the alkylation. U.S.Pat. Nos. 5,420,093 and 5,444,175 sought to combine the particulatecontact material and the catalyst by impregnating a mineral or organicsupport particulate with sulfuric acid.

[0009] Various static systems have been proposed for contactingliquid/liquid reactants, for example, U.S. Pat. Nos. 3,496,996;3,839,487; 2,091,917; and 2,472,578. However, the most widely usedmethod of mixing catalyst and reactants is the use of variousarrangements of blades, paddles, impellers and the like that vigorouslyagitate and blend the components together, for example, see U.S. Pat.Nos. 3,759,318; 4,075,258; and 5,785,933.

[0010] The present application presents a significant advance in thetechnology relating to alkylation and, in particular, to petroleumrefining paraffin alkylation by providing both an effective method forthe alkylation, novel olefinic feed and an apparatus for obtaining ahigh degree of contact between the liquid catalyst and the fluidreactants without mechanical agitation thereby eliminating shaft seals,reducing costs and improving acid product separation.

SUMMARY OF THE INVENTION

[0011] There are two aspects to the present invention. The first aspectis a process for the alkylation of paraffin, preferably isoparaffin witholefin or olefin precursor comprising contacting a fluid systemcomprising acid catalyst, alkane and olefin in concurrent flow,preferably downflow into contact in a reaction zone with internalpacking, such as a disperser (as hereinafter described) under conditionsof temperature and pressure to react said isoparaffin and said olefin toproduce an alkylate product. Preferably, the fluid system comprises aliquid and is maintained at about its boiling point in the reactionzone.

[0012] The second aspect of the present invention focuses on the olefinin the alkylation which is characteristic of an olefin precursor. Theolefin precursor is an oligomer of one or more tertiary olefins such asthe dimer, trimer, etc. of isobutene or a material which corresponds tosaid oligomer. In a particular embodiment, the present alkylationemploys oligomers of tertiary olefins as the olefin component of thealkylation with isoalkanes.

[0013] It has been surprisingly discovered that olefin reactants thatcorrespond to oligomers of olefins (for example, the longer chainoligomers of olefins made by polymerizing shorter chain olefins) whenreacted in an acid alkylation with an isoalkane react on a molar basiswith the constituent olefins of the oligomer, rather through theoligomers, per se, to produce alkylate product of the constituentolefin(s) and the isoalkane and not the alkylate of the oligomer per seas expected. The reaction may be carried out in an apparatus comprisinga vertical reactor containing a disperser or other suitable packing inthe reaction zone which may comprise the entire column or a portionthereof.

BRIEF DESCRIPTION OF THE DRAWING

[0014] The FIGURE is a schematic representation of the first aspect ofthe present apparatus in which the present alkylation process may becarried out.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The reaction of oligomer of tertiary olefins with isoalkanes ison a molar basis with the constituent tertiary olefins of the oligomerrather than the oligomers. The alkylate product corresponds to thereaction of the tertiary olefin and isoalkanes.

[0016] For the purpose of illustration and not a limitation of theprocess, it is believed that instead of the expected reaction betweenthe oligomer and the isoalkane, the oligomer is cracked into its olefincomponents which react with the isoalkane on a molar basis:

[0017] 1) diisobutene+2 isobutane→2 isooctane (2,2,4-trimethyl pentane)

[0018] 2) triisobutene+3 isobutane→3 isooctane (2,2,4-trimethyl pentane)

[0019] The conventional view had been that the product of 1) would be aC₁₂ alkane and the product of 2) would be a C₁₆ alkane whereas theproduct of reactions 1) and 2) is the same and is indistinguishable froma conventional cold acid alkylation product of the reaction:

[0020] 3) 2 butene-2+2 isobutane→2 isooctane

[0021] 4) 3 butene-2+3 isobutane→3 isooctane

[0022] The great advantage of the present invention is that althoughacid alkylations are extremely exothermic and require substantialrefrigeration to maintain the reaction temperature in optimum range toprevent side reactions, the present reaction of the oligomers with theisoalkane to produce the alkylate in the same yields required lessrefrigeration making the process less expensive for the same yield ofuseful product.

[0023] One particular method of producing oligomer is that carried outin a catalytic distillation, for example, units formerly used to produceMTBE can readily be converted to producing oligomer merely by changingthe feed to the reactor since the same catalyst serves both reactions.

[0024] Preferably, the oligomer comprises C₈ to C₁₆ olefinscorresponding to oligomer prepared from C₃ to C₅ olefin. In a preferredembodiment the oligomer has 6 to 16 carbon atoms and corresponds tooligomers which are prepared from C₄ to C₅ olefins.

[0025] The widest use of the paraffin alkylation is for the preparationof a C₈ gasoline component. The feed to this process is usually normalbutene and tertiary butane contained in a “cold acid” reaction usuallywith sulfuric acid or HF. The normal butene (butene-2,l for example) isa component of light naphtha along with normal butane, isobutane andtertiary butene. The separation of the normal butene from the isobutenecan be effected by fractionation with difficulty because of their closeboiling point. A preferred way to separate these olefin isomers or thoseof the C₅ analogs is to react the more reactive tertiary olefin to forma heavier product which is easily separated from the normal olefins byfractionation.

[0026] Heretofore, the tertiary olefin was reacted with a lower alcohol,such as methanol or ethanol, to form ethers, such as methyl tertiarybutyl ether (MTBE), ethyl tertiary butyl ether (ETBE), tertiary amylmethyl ether (TAME) which have been used as gasoline octane improversbut are being phased out because of health concerns.

[0027] The oligomerization of the tertiary olefin is also a preferredreaction when carried out on a naphtha stream with the separation ofnormal olefin being easily achieved by fractionation from the heavier(higher boiling) oligomers (mainly dimer and trimer). The oligomers maybe used as gasoline components but there are limits to the amount ofolefin material desirable or allowed in gasoline and it is frequentlynecessary to hydrogenate the oligomers for use in gasoline. The mostdesirable component for gasoline blending is C₈, e.g., isoctane (2,2,4trimethyl pentane).

[0028] The oligomer may be cracked back to the original tertiary olefinsand used in cold acid reaction. However, the present invention has foundthat it is not necessary to crack the oligomer which may constitute theolefin feed to cold acid reaction with the alkane or may be co-fed withmono olefins. As noted above the result is the same product as the monoolefin alone with the additional benefit of a less exothermic overallreaction requiring less refrigeration and, hence, a lower energy costfor the alkylation.

[0029] The oligomerization process produces a heat of reaction that doesnot require the magnitude of heat removal as in the cold acid process.In fact, when the oligomerization is carried out in a catalyticdistillation type reaction, the heat of reaction is removed as boilup,which in this type of reaction is the lower boiling mono olefins andalkanes which are being separated from the oligomer. Thus, even thoughthere is heat produced in the oligomerization it is of no cost to theproduction of the gasoline since it is used in the fractionation, andthe operating cost of the alkylation unit is reduced by the use ofoligomer to replace some or all of the conventional short chain olefin.

[0030] In a preferred embodiment of the present alkylation process, alight naphtha stream comprising normal and tertiary olefins is contactedwith an acid resin catalyst under oligomerization conditions topreferentially react a portion of the tertiary olefins with themselvesto form oligomers, and feeding said oligomers to an alkylation zone withan isoalkane in the presence of an acid alkylation catalyst to producean alkylation product comprising the alkylate of said tertiary olefinand said isoalkane.

[0031] The oligomerization may be carried out in a partial liquid phasein the presence of an acid cation resin catalyst either in straight passtype reaction or in a catalytic distillation reaction where there isboth a vapor and liquid phase and a concurrent reaction/fractionation.Preferably, the feed is a C₄-C₅, C₄ or C₅ light naphtha cut. Thetertiary olefins may include isobutene, and isoamylenes and are morereactive than the normal olefin isomers and are preferentiallyoligomerized. The primary oligomer products are dimers and trimers. Theisoalkanes preferably comprise isobutane, isopentane or mixturesthereof.

[0032] When a straight pass reactor is used, such as that disclosed inU.S. Pat. Nos. 4,313,016; 4,540,839; 5,003,124; and 6,335,473,l theentire effluent comprising the oligomer, normal olefins and isoalkanesmay be fed to an acid alkylation reaction. The normal alkanes are inertunder the conditions of the present alkylation. Under alkylationconditions the isoalkane reacts with the normal olefin to form alkylateproduct and with the individual constituent olefins of the oligomers toform the alkylate product. The implication of the result of the presentprocess is that the oligomers are dissociated or in some manner maketheir constituent olefins available for reaction with isoalkanes. Thus,the reaction will produce:

[0033] 1) isobutene oligomer+isobutane→isooctane;

[0034] 2) isobutene oligomer+isopentane→branched C₉ alkanes;

[0035] 3) isoamylene oligomer+isobutane→branched C₉ alkanes;

[0036] 4) isoamylene oligomer+isopentane→branched C₁₀ alkanes;

[0037] whereas it would have been expected that reaction 1) wouldproduce at least or mostly C₁₂ alkanes, reaction 2) would produce atleast or mostly C₁₃ alkanes, reaction 3) would produce at least ormostly C₁₄ alkanes, and reaction 4) would produce at least or mostly C₁₅alkanes.

[0038] When a catalytic distillation reaction such as that disclosed inU.S. Pat. Nos. 4,242,530 or 4,375,576 is employed for theoligomerization, the oligomer is separated from the lower boiling normalolefins and alkanes in the reaction product by concurrent fractionation.The streams, normal olefins and alkanes (overheads) and oligomers(bottoms), may be united or individually fed to the alkylation or may beused individually with at least the oligomer being fed to thealkylation.

[0039] The present invention offers an improved contacting apparatus andprocess for producing and separating an alkylate product using sulfuricacid as catalyst. This same or similar device may also be used withother acids or acid mixtures.

[0040] The present process preferably employs a downflow reactor packedwith contacting internals or packing material (which may be inert orcatalytic) through which passes a concurrent multi phase mixture ofsulfuric acid, hydrocarbon solvent and reactants at the boiling point ofthe system. The system comprises a hydrocarbon phase and anacid/hydrocarbon emulsion phase. A significant amount of sulfuric acidis held up on the packing. Reaction is believed to take place betweenthe descending hydrocarbon phase and the sulfuric acid dispersed on thepacking. Olefin continuously dissolves into the acid phase and alkylateproduct is continuously extracted into the hydrocarbon phase. Adjustingthe pressure and hydrocarbon composition controls the boiling pointtemperature. The reactor is preferentially operated vapor continuous butmay also be operated liquid continuous. The pressure is preferentiallyhigher at the top of the reactor than at the bottom.

[0041] Adjusting the flow rates and the degree of vaporization controlsthe pressure drop across the reactor. Multiple injection of olefin ispreferred. The type of packing also influences the pressure drop due tothe acid phase hold-up. The product mixture before fractionation is thepreferred circulating solvent. The acid emulsion separates rapidly fromthe hydrocarbon liquid and is normally recycled with only a few minutesresidence time in the bottom phase separator. Because the products arein essence rapidly extracted from the acid phase (emulsion), thereaction and/or emulsion promoters used in conventional sulfuric acidalkylation processes may be added without the usual concern for breakingthe emulsion. The process may be described as hydrocarbon continuous asopposed to acid continuous.

[0042] Preferably, the disperser comprises a conventional liquid-liquidcoalescer of a type which is operative for coalescing vaporized liquids.These are commonly known as “mist eliminators” or “demisters”, however,in the present invention the element functions to disperse the fluidmaterials in the reactor for better contact. A suitable dispersercomprises a mesh such as a co-knit wire and fiberglass mesh. Forexample, it has been found that a 90 needle tubular co-knit mesh of wireand multi-filament fiberglass such as manufactured by Amistco SeparationProducts, Inc. of Alvin, Texas, can be effectively utilized, however, itwill be understood that various other materials such as co-knit wire andmulti filament teflon (Dupont™), steel wool, polypropylene, PVDF,polyester or various other co-knit materials can also be effectivelyutilized in the apparatus. Various wire screen type packings may beemployed where the screens are woven rather than knitted. Otheracceptable dispersers include perforated sheets and expanded metals,open flow cross channel structures which are co-woven with fiberglass orother materials such as polymers co-knit with the wire mesh expanded orperforated sheets. Additionally the multi-filament component may becatalytic. The multi-filament catalytic material may be polymers, suchas sulfonated vinyl resin (e.g., Amberlyst) and catalytic metals such asNi, Pt, Co, Mo, Ag.

[0043] The disperser comprises at least 50 volume % open space up toabout 97 volume % open space. Dispersers are position within thereaction zone in the reactor. Thus, for example, the multi filamentcomponent and the structural element, e.g., knit wire, should compriseabout 3 volume % to about 50 volume % of the total disperser, theremainder being open space.

[0044] Suitable dispersers include structured catalytic distillationpackings which are intended to hold particulate catalysts, or structureddistillation packings composed of a catalytically active material, suchas that disclosed in U.S. Pat. No. 5,730,843 which is incorporatedherein in its entirety and which discloses structures that have a rigidframe made of two substantially vertical duplicate grids spaced apartand held rigid by a plurality of substantially horizontal rigid membersand a plurality of substantially horizontal wire mesh tubes mounted tothe grids to form a plurality of fluid pathways among the tubes, saidtubes being empty or containing catalytic or non catalytic materials;and structured packings which are catalytically inert which aretypically constructed of corrugated metal bent at various angles, wiremesh which is crimped, or grids which are horizontally stacked one ontop of the other, such as disclosed in U.S. Pat. No. 6,000,685 which isincorporated herein in its entirety and which discloses contactstructures comprising a plurality of sheets of wire mesh formed into veeshaped corrugations having flats between the vees, said plurality ofsheets being of substantially uniform size having the peaks oriented inthe same direction and substantially in alignment, said sheets beingseparated by a plurality of rigid members oriented normally to and saidresting upon said vees.

[0045] Other suitable dispersers include: (A) random or dumpeddistillation packings which are: catalytically inert dumped packingscontain higher void fraction and maintain a relatively large surfacearea, such as, Berl Saddles (Ceramic), Raschig Rings (Ceramic), RaschigRings (Steel), Pall rings (Metal), Pall rings (Plastic, e.g.polypropylene) and the like and catalytically active random packingswhich contain at least one catalytically active ingredient, such as Ag,Rh, Pd, Ni, Cr, Cu, Zn, Pt, Tu, Ru, Co, Ti, Au, Mo, V, and Fe as well asimpregnated components such a metal-chelate complexes, acids such asphosphoric acid, or bonded, inorganic, powdered materials with catalyticactivity; and (B) monoliths which are catalytically inert or activewhich are structures containing multiple, independent, vertical channelsand may be constructed of various materials such as plastic, ceramic, ormetals, in which the channels are typically square; however, othergeometries could be utilized, being used as such are coated withcatalytic materials.

[0046] The hydrocarbon feedstock undergoing alkylation by the method ofthe present invention is provided to the reaction zone in a continuoushydrocarbon phase containing effective amounts of olefinic andisoparaffinic starting materials which are sufficient for forming analkylate product. The olefin:isoparaffin mole ratio in the total reactorfeed should range from about 1:1.5 to about 1:30, and preferably fromabout 1:5 to about 1:15. Lower olefin:isoparaffin ratios may also beused.

[0047] The olefin component should preferably contain 2 to 16 carbonatoms and the isoparaffin component should preferably contain 4 to 12carbon atoms. Representative examples of suitable isoparaffins includeisobutane, isopentane, 3-methylhexane, 2-methylhexane,2,3-dimethylbutane and 2,4-dimethylhexane. Representative examples ofsuitable olefins include butene-2, isobutylene, butene-1, propylene,pentenes, ethylene, hexene, octene, and heptene, merely to name a fewand as described above may be oligomers of these olefins.

[0048] In the fluid process the system uses hydrofluoric or sulfuricacid catalysts under relatively low temperature conditions. For example,the sulfuric acid alkylation reaction is particularly sensitive totemperature with low temperatures being favored in order to minimize theside reaction of olefin polymerization. Petroleum refinery technologyfavors alkylation over polymerization because larger quantities ofhigher octane products can be produced per available light chainolefins. Acid strength in these liquid acid catalyzed alkylationprocesses is preferably maintained at 88 to 94% by weight using thecontinuous addition of fresh acid and the continuous withdrawal of spentacid. Other acids such as solid phosphoric acid may be used bysupporting the catalysts within or on the packing material.

[0049] Preferably, the process of the present invention shouldincorporate relative amounts of acid and hydrocarbon fed to the top ofthe reactor in a volumetric ratio ranging from about 0.01:1 to about2:1, and more preferably in a ratio ranging from about 0.05:1 to about0.5:1. In the most preferred embodiment of the present invention, theratio of acid to hydrocarbon should range from about 0.1:1 to about0.3:1.

[0050] Additionally, the dispersion of the acid into the reaction zoneshould occur while maintaining the reactor vessel at a temperatureranging from about 0° F. to about 200° F., and more preferably fromabout 35° F to about 130° F. Similarly, the pressure of the reactorvessel should be maintained at a level ranging from about 0.5 ATM toabout 50 ATM, and more preferably from about 0.5 ATM to about 20 ATM.Most preferably, the reactor temperature should be maintained within arange from about 40° F. to about 110° F. and the reactor pressure shouldbe maintained within a range from about 0.5 ATM to about 5 ATM.

[0051] In general, the particular operating conditions used in theprocess of the present invention will depend to some degree upon thespecific alkylation reaction being performed. Process conditions such astemperature, pressure and space velocity as well as the molar ratio ofthe reactants will affect the characteristics of the resulting alkylateproduct and may be adjusted in accordance with parameters known to thoseskilled in the art.

[0052] An advantage of operating at the boiling point of the presentreaction system is that there is some evaporation which aids indissipating the heat of reaction and making the temperature of theincoming materials closer to that of the materials leaving the reactoras in an isothermal reaction.

[0053] Once the alkylation reaction has gone to completion, the reactionmixture is transferred to a suitable separation vessel where thehydrocarbon phase containing the alkylate product and any unreactedreactants is separated from the acid. Since the typical density for thehydrocarbon phase ranges from about 0.6 g/cc to about 0.8 g/cc and sincedensities for the acid generally fall within the ranges of about 0.9g/cc to about 2.0 g/cc, the two phases are readily separable byconventional gravity settlers. Suitable gravitational separators includedecanters. Hydrocyclones, which separate by density difference, are alsosuitable.

[0054] One alkylation embodiment is shown in the FIGURE which is asimplified schematic representation of the apparatus and flow of theprocess. Such items as valves, reboilers, pumps, etc., have beenomitted.

[0055] The reactor 10 is shown containing a disperser mesh 40. Thepresent dispersers achieve radial dispersion of the fluid or fluidizedmaterials in the reactor. The feed to the reactor comprises an olefinfed via line 12 such as n-butene and an isoparaffin (e.g., isobutane)fed via line 14 through line 52. Preferably a portion of the olefin isfed along the reactor via lines 16 a, 16 b, and 16 c. A liquid acidcatalyst such as H₂SO₄ is fed via line 56 and make-up acid may besupplied through line 38. The hydrocarbon reactants are fed to thereactor which is preferably a generally cylindrical column via line 58and through appropriate dispersing means (not shown) into the dispersermesh 40, for example, a co-knit wire and fiberglass mesh.

[0056] The hydrocarbon reactants and non reactive hydrocarbons (e.g.,normal butane) are intimately contacted with the acid catalyst as thealkylation proceeds. The reaction is exothermic. The pressure as well asthe quantities of reactants are adjusted to keep the system componentsat the boiling point but partially in the liquid phase as the systemcomponents pass down flow through the reactor in mixed vapor/liquidphase and out through line 18 into decanter 30. In the decanter thesystem components are separated into an acid phase 46 containing thecatalyst, a hydrocarbon phase 42 containing the alkylate, unreactedolefin and unreacted isoparaffin, and non reactive hydrocarbons and avapor phase 44 which may contain some of each of the components and anylighter hydrocarbon components which are removed from the system vialine 50 for further handling as appropriate.

[0057] Most of the acid phase is recycled via line 24 and 56 into thereactor. Make-up acid may be added via line 38 and build-up spent acidremoved via line 48.

[0058] The hydrocarbon liquid phase is removed via line 22 with aportion recycled to the top of the reactor via line 28. The remainder ofhydrocarbon phase is fed to distillation column 20 via line 26 where itis fractionated. Normal butane, if present in the feed, can be removedvia line 36 and the alkylate product is removed via line 34. Theoverheads 32 are primarily unreacted isoalkane which is recycled vialine 52 to the top of reactor 10.

Experimental Set up for Alkylation of Isoparaffin+Olefin

[0059] For the following examples the laboratory reactor is 15 feet highby 1.5 inches diameter. It is packed with varying amounts and types ofpacking material. The H₂SO₄ inventory is about 1 liter depending on theholdup of the packing used. The surge reservoir is about 3 liters andpasses all the acid plus liquid hydrocarbon out the bottom to circulatea two-phase mixture with a single pump. Feeds are introduced at the topof the reactor to flow down with the recycle mixture. Vapor is producedby heat of reaction plus ambient heat gains and helps force the liquidsdown through the packing creating great turbulence and mixing. Most ofthe vapors are condensed after the reactor outlet. Uncondensed vapor andliquid hydrocarbon product passes through an acid de-entrainer thenthrough the backpressure regulator to the de-isobutanizer. Mass flowmeters are used for feed flows and a Doppler meter measures thecirculation rate. Liquid products from the de-isobutanizer are weighed.However, the vent flow rate is estimated as being the difference betweenthe mass flow metered feed in and the weighed liquid products out. GCanalyzes all hydrocarbon products, including the vent. Titration is usedfor spent acid assay.

Operation

[0060] In the following examples the experimental unit circulateshydrocarbon and acid down flow at the boiling point of the hydrocarbonspresent. Pressure and temperature readings are logged electronically.The reactor outlet temperature and pressure are used to calculate theamount of iC₄ in the recycle hydrocarbon using an iC₄ /Alkylate flashcalculation.

[0061] A backpressure regulator that passes both product liquid andvapor to the de-isobutanizer tower, maintains the pressure. A smallamount of N₂ may be used primarily to keep acid from backing up into thefeed line. However, too much N₂ will cause a decrease in product qualityby diluting reactive isoparaffin in the vapor phase.

[0062] The circulation pump in the experimental setup circulates boththe acid emulsion layer and the liquid hydrocarbon layer. Alternatively,these two phases may be pumped separately.

[0063] The acid inventory is maintained by momentarily diverting theentire recycle through a measuring tube using a three-way valve. Thetrapped material settles in seconds to form two layers. The volumepercent acid layer and hydrocarbon layer is then used in conjunctionwith the Doppler meter reading to estimate the volumetric circulationrates of both phases.

[0064] The DP (pressure higher at the top or reactor inlet) ismaintained between 0 and 3 psi by manipulating the circulation rates andthe heat balance around the unit. Different packing usually requiresdifferent vapor and liquid flow rates to load to the same DP. Most ofthe time, the ambient heat gains and the heat of reaction provideadequate vapor (mostly iC₄) loading.

[0065] Because of refrigeration constraints, about 1-3 lbs/hr of extraliquid iC₄ may be introduced with the feed to provide some trim cooling.This excess iC₄ is relatively small and does not significantly affectthe iC₄ / Olefin ratio since the circulating hydrocarbon rates aretypically on the order of 100 - 200 pounds per hour. It is thecirculating hydrocarbon flow rate and composition that dominates the iC₄ratios to everything else. Feed olefin C4's Olefin in - lbs/hr 0.25-.50 Alky out - lbs/hr 0.50-1.2  Rxn Temp out - F. 50-60 Rxn Psig out  6-16DP - Psi 0.5-3.0 Recycle rates: Acid phase - L/min 0.3-1   HC phase -L/min 1-3 Wt % iC4 in HC recycle 75-45 Wt % H2SO4 in Spent acid 83-89 Wt% H2O in Spent acid 2-4 Fresh acid addition - lbs/gal alky 0.3-0.5Packing Type 1 or 2 - see notes below Packing Hgt in feet 10-15 Packdensity lbs/ft3  5-14

Example 1

[0066] Refinery C4 Olefins used as feedstocks 38% iB in To the Lab Unit:Low iB total olefins methane 0.02 0.00 ethane 0.00 0.00 ethene 0.00 0.00propane 0.77 0.41 propene 0.14 0.16 propyne 0.02 0.00 propadiene 0.010.02 iso-butane 23.91 47.50 iso-butene 0.90 15.90 1-butene 20.02 10.491,3-butadiene 0.02 0.19 n-butane 22.63 10.79 t-2-butene 18.05 7.932,2-dm propane 0.09 0.00 1-butyne 0.00 0.01 m-cyclopropane 0.03 0.03c-2-butene 12.09 5.43 1,2-butadiene 0.00 0.01 3M-1-butene 0.26 0.04iso-pentane 0.98 0.02 1-pentene 0.06 0.82 2M-1-butene 0.01 0.01n-pentane 0.01 0.03 t-2-pentene 0.00 0.08 c-2-pentene 0.00 0.00t-3-pentadiene 0.00 0.08 c-1,3-pentadiene 0.00 0.00 unknowns 0.01 0.08100.00 100.00

[0067] Comparison of Refinery produced Alkylate with Lab Unit resultsusing similar low iB C4 feed Plant A Plant B Lab 1 Lab 2 iC5 6.27 2.702.51 2.78 2,3-dmb 4.05 2.84 2.80 3.02 C6 1.63 1.19 1.00 1.15 2,2,3-tmb0.20 0.17 0.18 0.19 C7 7.17 5.55 4.35 4.35 TM C8 53.88 61.76 66.84 66.93DM C8 12.27 12.47 12.69 12.44 TM C9 5.04 4.22 2.89 2.74 DM C9 0.57 1.010.29 0.18 TM C10 1.14 0.91 0.70 0.64 UNK C10 0.51 0.54 0.29 0.29 TM C110.99 0.77 0.69 0.71 UNK C11 1.09 0.02 0.00 0.00 C12 4.37 1.71 4.72 4.60C13 0.00 1.58 0.00 0.00 C14 0.03 1.57 0.05 0.00 C15 0.00 0.13 0.00 0.00HV'S 0.05 0.04 0.00 0.00 UNK 0.74 0.83 0.00 0.00 sum 100.00 100.00100.00 100.00 Av MW 113.4 116.0 114.9 114.6 Bromine no. <1 <1 <1 <1Total Sulfur ppm <10 <10 <10 <10 TOTAL % TM 61.05 67.66 71.12 71.01 TMC8/DM C8 (ratio) 4.39 4.95 5.27 5.38 TM C9/DM C9 (ratio) 8.85 4.19 10.0815.57

[0068] Typical vent analysis: wt % hydrogen 0.000 oxygen 0.124 nitrogen3.877 methane 0.019 carbon monoxide 0.000 carbon dioxide 0.000 ethane0.000 ethene 0.000 ethyne 0.000 propane 1.066 propene 0.000 propadiene0.000 iso-butane 81.233 iso-butene 0.021 1-butene 0.000 1,3-butadiene0.031 n-butane 3.398 t-2-butene 0.000 m-cyclopropane 0.000 c-2-butene0.000 iso-pentane 0.968 1-pentene 0.000 n-pentane 0.000 C5+ 0.391

Example 2

[0069] Effect of Isobutylene (iB) on Alky Quality lab 1 100% iB 38% iBlow iB iC5 3.66 3.97 2.78 2,3-dmb 3.60 3.56 3.02 C6 1.42 0.52 1.152,2,3-tmb 0.40 0.23 0.19 C7 5.27 5.08 4.35 TM C8 50.79 56.95 66.93 DM C811.77 12.64 12.44 TM C9 6.07 4.22 2.74 DM C9 0.58 0.45 0.18 TM C10 2.061.33 0.64 UNK C10 1.14 0.67 0.29 TM C11 2.54 1.28 0.71 UNK C11 1.00 0.000.00 C12 8.30 8.99 4.60 C13 0.07 0.00 0.00 C14 0.28 0.14 0.00 C15 0.120.00 0.00 HV'S 0.38 0.00 0.00 UNK 0.54 0.00 0.00 sum 100.00 100.00100.00 Av MW 119.1 117.3 114.9 Bromine no. ˜1 <1 <1 Total Sulfur ppm <10<10 <10 TOTAL % TM 61.46 63.77 71.12 TM C8/DM C8 4.31 4.51 5.27 TM C9/DMC9 10.51 9.34 10.08

Example 3

[0070] Propylene + iC4 Alkylation Sample Point product propane 0.01iso-butane 9.25 n-butane 0.32 iso-pentane 0.97 n-pentane 0.00 2,3-dmbutane 2.07 2M-pentane 0.30 3M-pentane 0.14 n-hexane 0.00 2,4-dm pentane15.59 2,2,3-tm butane 0.04 3,3-dm pentane 0.01 cyclohexane 0.002M-hexane 0.34 2,3-dm pentane 48.97 1,1-dm cyclopentane 0.00 3M-hexane0.35 2,2,4-tm pentane 3.42 n-heptane 0.00 2,5-dm hexane 0.37 2,4-dmhexane 0.56 2,3,4-tm pentane 1.52 2,3,3-tm pentane 1.21 2,3-dm hexane0.64 2,2,5-tm hexane 0.68 2,3,4-tm hexane 0.13 2,2-dm heptane 0.012,4-dm heptane 0.03 2,6-dm heptane 0.03 2,2,4-tm-heptane 1.833,3,5-tm-heptane 1.70 2,3,6-tm-heptane 1.16 2,3,5-tm-heptane 0.16tm-heptane 1.00 2,2,6-trimethyloctane 2.32 C8s 0.20 C9s 0.20 C10s 0.98C11s 1.62 C12s 1.73 C13s 0.09 C14s 0.05 C15s 0.01 unknowns 0.01 heavies0.00 100.00

Example 4

[0071] Isobutane + pentene 1 alkylation product Wt % C5 5.03 2,3-dmb0.74 C6 0.35 DM C7 1.14 C7 0.17 TM C8 22.26 DM C8 3.70 TM C9 52.40 DM C96.72 TM C10 1.51 UNK C10 0.56 TM C11 0.16 UNK C11 0.38 C12 3.68 C13 0.33C14 0.11 C15 0.08 HV'S 0.03 UNK 0.63 100.00 Avg MW 123.2 expected MW 128feed olefin #/hr 0.25 Alky product #/hr 0.47

Example 5

[0072] Oligomerization product from C4 feedstock with 38% iB in totalolefins. (This product was in turn used as iso-butane 48.8 iso-butene +1-butene 1.6 n-butane 11.2 t-2-butene 14.3 c-2-butene 6.5 iso-pentane1.0 t-2-pentene 0.1 unknowns 1.5 2,4,4-tm-1-pentene 4.72,4,4-tm-2-pentene 1.3 other C8's 3.4 grouped C12's 4.4 grouped C16's1.2 100.0

[0073] Oligomerization effect on Alky products using C4 feed with iB=38%of Olefins before after iC5 3.97 2.39 2,3-dmb 3.56 2.87 C6 0.52 1.172,2,3-tmb 0.23 0.20 C7 5.08 4.95 TM C8 56.95 58.34 DM C8 12.64 12.80 TMC9 4.22 4.15 DM C9 0.45 0.35 TM C10 1.33 1.29 UNK C10 0.67 0.57 TM C111.28 1.41 UNK C11 0.00 0.00 C12 8.99 9.41 C13 0.00 0.00 C14 0.14 0.11C15 0.00 0.00 HV'S 0.00 0.00 UNK 0.00 0.00 sum 100.00 100.00 Av MW 117.3118.3 Bromine no. <1 <1 Total Sulfur ppm <10 <10 TOTAL % TM 63.77 65.19TM C8/DM C8 4.51 4.56 TM C9/DM C9 9.34 11.75 Operating conditions:Olefin in - lbs/hr .25 .25 Alky out - lbs/hr .53 .53 Rxn Temp out - F.52.0 52.2 Rxn Psig out 12.2 11.8 DP - Psi ˜1 ˜1 Recycle rates: Acidphase - L/min 1.0 1.0 HC phase - L/min 2.6 2.6 % 69 67 iC4 in HC recyclePacking Type 2 2 Packing Hgt in feet 15 15 Pack density lbs/ft3 7 7

Example 6

[0074] Alkylate quality from Isobutene + Isobutane or Oligomers of iB +iC4. iB DIB TIB+ IC5 3.66 3.97 3.41 2,3-dmb 3.60 3.70 3.18 C6 1.42 1.361.53 2,2,3-tmb 0.40 0.38 0.27 C7 5.27 4.96 6.39 TM C8 50.79 47.93 38.35DM C8 11.77 8.92 12.91 TM C9 6.07 6.60 10.31 DM C9 0.58 0.81 1.10 TM C102.06 3.09 3.29 UNK C10 1.14 1.18 1.35 TM C11 2.54 2.53 2.72 UNK C11 1.001.79 0.00 C12 8.30 10.51 14.97 C13 0.07 0.31 0.07 C14 0.28 1.47 0.14 C150.12 0.29 0.00 HV'S 0.38 0.19 0.00 UNK 0.54 0.01 0.00 Sum 100.00 100.00100.00 Av MW 119.1 122.1 122.9 Bromine no. ˜1 ˜1 ˜1 Total Sulfur ppm <10<10 <10 TOTAL % TM 61.46 60.15 54.67 TM C8/DM C8 4.31 5.37 2.97 TM C9/DMC9 10.51 8.15 9.37 Operating conditions: Feed olefin iB DIB TIB+ Olefinin - lbs/hr 0.25 0.40 0.25 Alky out - lbs/hr 0.49 0.78 0.48 Rxn Tempout - F. 52 51.6 51.7 Rxn psig out 13 13.5 5.7 DP - psi 2.5 1.1 ˜1Recycle rates: Acid phase- L/min 0.8 0.5 1.0 HC phase - L/min 1.8 1.43.0 % 73 76 45 iC4 in HC recycle Packing Type 1 1 2 Packing Hgt in feet10 10 15 Pack density lbs/ft3 6 6 7

Example 7

[0075] Expected vs. actual alkylation product MW's and moles iC4 uptakewith various olefins (e.g. in theory 1 mole of C6 olefin should reactwith 1 mole of iC4 to form a C10 alkylate; MW=142)

[0076] Results indicate depolymerization generating more and lower MWolefins that combine with additional iC4. Moles iC4 uptake per moleOlefin fed Average product MW Olefin Expected Actual Expected ActualHexene-1 1.0 1.2 142 129 Octene-1 1.0 1.4 170 135 Di-isobutylene 1.0 1.8170 122 Tri-isobutylene+ 1.0 2.6 226 123

Example 8

[0077] Isobutane + pentene 1 alkylation product Wt % IC5 5.03 2,3-dmb0.74 C6 0.35 DM C7 1.14 C7 0.17 TM C8 22.26 DM C8 3.70 TM C9 52.40 DM C96.72 TM C10 1.51 UNK C10 0.56 TM C11 0.16 UNK C11 0.38 C12 3.68 C13 0.33C14 0.11 C15 0.08 HV'S 0.03 UNK 0.63 100.00 Avg MW 123.2 expected MW 128feed olefin #/hr 0.25 Alky product #/hr 0.47

The invention claimed is:
 1. A paraffin alkylation process comprisingcontacting alkane and olefin in concurrent flow in the presence of anacid catalyst into contact with a disperser under conditions oftemperature and pressure to react said alkane and said olefin to producealkylate product.
 2. The process according to claim 1 wherein saidalkane comprises isoalkane
 3. The process according to claim 1 whereinthe acid catalyst comprises fluid.
 4. The process according to claim 2wherein said fluid comprises liquid.
 5. The process according to claim 4wherein the conditions are such as to maintain said liquid at about itsboiling point.
 6. The process according to claim 5 is hydrocarboncontinuous.
 7. The process according to claim 5 wherein said isoalkanecomprises 4 to 8 carbon atoms and said olefin comprises 3 to 16 carbonatoms.
 8. The process according to claim 7 wherein flow is downward. 9.The process according to claim 8 wherein said temperature is from about0° F. to 200° F.
 10. The process according to claim 4 wherein saiddisperser comprises mesh of co-knit wire and polymer.
 11. An isoparaffinalkylation process comprising contacting a system comprising acid,isoalkane and olefin in concurrent downflow under conditions oftemperature and pressure to maintain said liquid system at about itsboiling point through a reaction zone packed with contacting internals.12. The process according to claim 11 is hydrocarbon continuous.
 13. Theprocess according to claim 12 wherein said isoalkane comprises 4 to 8carbon atoms and said olefin comprises 3 to 16 carbon atoms.
 14. Theprocess according to claim 12 wherein said system comprises mixedliquid/vapor phases.
 15. The process according to claim 14 wherein saidmixed liquid/vapor phases comprise hydrocarbons.
 16. The processaccording to claim 14 wherein said mixed liquid/vapor phases compriseacid/hydrocarbon emulsion.
 17. A paraffin alkylation process comprisingcontacting an oligomer comprising at least two constituent olefins withan isoalkane in the presence of an acid alkylation catalyst underalkylation conditions and recovering a product comprising an alkylatecorresponding to the alkylation product of said isoalkane and saidconstituent olefins.
 18. The process according to claim 17 wherein saidoligomer comprises tertiary olefin constituents.
 19. The processaccording to claim 18 wherein said oligomer comprises 6 to 16 carbonatoms.
 20. The process according to claim 19 wherein said isoalkanecomprises 4 to 5 carbon atoms.
 21. The process according to claim 20wherein said oligomer comprises an isobutene constituent.
 22. Theprocess according to claim 17 wherein said olefin comprises an oligomerhaving 6 carbon atoms.
 23. The process according to claim 20 whereinsaid oligomer comprises an isoamylene constituent.
 24. The processaccording to claim 20 wherein said tertiary olefin comprises isobuteneand isoamylene constituents.
 25. The process according to claim 21wherein said isoalkane comprises isobutane.
 26. An integrated processfor the production of alkylate comprising contacting a stream comprisingnormal and tertiary olefins with an acid cation resin catalyst underoligomerization conditions to preferentially react a portion of thetertiary olefins with themselves to form oligomers and feeding saidoligomers and isoalkane to an alkylation zone under alkylationconditions in the presence of an acid alkylation catalyst to produce analkylation product comprising the alkylate of said tertiary olefins andsaid isoalkane.
 27. The process according to claim 26 wherein saidstream comprises a light naphtha C₄-C₅ cut, a C₄ cut or a C₅ cut. 28.The process according to claim 27 wherein said stream comprisesisobutene.
 29. The process according to claim 27 wherein said streamcomprises isoamylenes.
 30. The process according to claim 27 whereinsaid isoalkane comprises isobutane, isopentane or mixtures thereof. 31.The process according to claim 28 wherein said isoalkane comprisesisobutane, isopentane or mixtures thereof.
 32. The process according toclaim 29 wherein said isoalkane comprises isobutane, isopentane ormixtures thereof.
 33. The process according to claim 27 wherein the acidalkylation catalyst comprises sulfuric acid.
 34. The process accordingto claim 33 wherein said alkylation is carried out at a temperature inthe range of range from about 0° F. to about 200° F. and a pressure inthe range of from about 0.5 ATM to about 50 ATM.
 35. The processaccording to claim 27 wherein said acid alkylation catalyst comprisesHF.
 36. The process according to claim 27 wherein said tertiary olefincomprises isobutene, isopentene or mixtures thereof, said isoalkanecomprises isobutane, isopentane or mixtures thereof, said acidalkylation is sulfuric acid and said alkylation is carried out at atemperature in the range of range from about 0° F. to about 200° F. anda pressure in the range of from about 0.5 ATM to about 50 ATM.
 37. Theprocess according to claim 36 wherein said alkylation product comprisesisooctane.
 38. A process for the production of alkylate comprising thesteps of reacting olefins with themselves to form oligomers andcontacting the oligomerization product with an alkane in the presence ofan alkylation catalyst to produce alkylate.
 39. The process according toclaim 38 wherein said alkylation catalyst is sulfuric acid.
 40. Theprocess according to claim 38 wherein said alkylation catalyst ishydrofluoric acid.
 41. The process according to claim 38 wherein theoligomerization product is in the vapor phase, the alkane is in theliquid phase and the alkylation catalyst is in the liquid phase.
 42. Theprocess according to claim 38 wherein the oligomerization product is inthe liquid phase, the alkane is in the vapor phase and the alkylationcatalyst is in the liquid phase.
 43. The process according to claim 38wherein the alkylation catalyst is in the solid phase.
 44. The processaccording to claim 38 wherein the alkylation catalyst is in the vaporphase.
 45. The process according to claim 38 wherein said olefinscomprise C₂ to C₁₆ olefins.
 46. The process according to claim 45wherein said olefins comprise C₂ to C₁₆ tertiary olefins.
 47. Theprocess according to claim 38 wherein said alkanes comprise iso alkanes.48. A process for the production of alkylate comprising the steps ofreacting C2 to C16 tertiary olefins with themselves to form oligomersand contacting the oligomerization product with isoalkane in thepresence of an acid alkylation catalyst to form alkylate.